Updated test cases compile flags for C translation units

tests/CMakeLists.txt

@@ -51,10 +51,11 @@ foreach(TEST_NAME ${TEST_CASES})
     target_compile_definitions(${TEST_NAME} PRIVATE
             $<$<EQUAL:${ENABLE_CXX_STD_20_TEST_CASES},1>:ENABLE_CXX_STD_20_TEST_CASES>)
     target_compile_options(${TEST_NAME} PRIVATE
+            $<$<COMPILE_LANGUAGE:CXX>:
             $<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:GNU>>:
             -Wno-unused-parameter -Wno-unused-private-field -Wno-unused-variable
             -Wno-attributes -Wno-nonnull -Wno-deprecated-enum-enum-conversion>
-            $<$<CXX_COMPILER_ID:MSVC>:/MP /W1 /bigobj /wd4624>)
+            $<$<CXX_COMPILER_ID:MSVC>:/MP /W1 /bigobj /wd4624>>)
     target_link_libraries(${TEST_NAME} PRIVATE ${CLANG_UML_TEST_LIBRARIES})
 endforeach()